• Animal Systematics, Evolution and Diversity
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• v.28 no.2
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• pp.133-136
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• 2012

The objective of this study was to determine the degree of mitochondrial DNA (mtDNA) divergence between two subspecies of $Mustela$ $sibirica$ from Korea ($M.$ $s.$ $coreanus$ on the Korean Peninsula and ($M.$ $s.$ $quelpartis$ on Jeju Island) and to examine the taxonomic status of ($M.$ $s.$ $quelpartis$. Thus, we obtained complete sequences of mtDNA cytochrome $b$ gene (1,140 bp) from the two subspecies, and these sequences were compared to a corresponding haplotype of ($M.$ $s.$ $coreanus$, downloaded from GenBank. From this analysis, it was observed that the sequences from monogenic ($M.$ $s.$ $quelpartis$ on Jeju Island were identical to the sequences of four ($M.$ $s.$ $coreanus$from four locations across the Korean Peninsula, and that the two subspecies formed a single clade; the average nucleotide distance between the two subspecies was 0.26% (range, 0.00 to 0.53%). We found that the subspecies $quelpartis$ is not genetically distinct from the subspecies $coreanus$, and that this cytochrome $b$ sequencing result does not support the current classification, distinguishing these two subspecies by pelage color. Further systematic analyses using morphometric characters and other DNA markers are necessary to confirm the taxonomic status of ($M.$ $s.$ $quelpartis$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.88-94
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• 1997

The mitochondrial DNA (mtDNA) restriction fragment length polymorphi는 (RFLPs) of five populations were analyzed to delineate the stocks of Penaeus chinensis (Osbeck) in the Yellow Sea. Comparison of P. chinensis with P. japonicus to clarify the nucleotide divergence between two species was also carried out. Based on the fragment patterns, three composite haplotypes were analyzed in P. chinensis mtDNA as four naplotypes were in P. japonicus. Most individuals of each P. chinensis population are shared by one dominant haplotype. Another two haplotypes haying variations at the C/a I and hull sites were also distributed evenly in the Korean and Chinese populations. It is suggested that the gene exchange occurring between populations in the Yellow Sea is frequent. Average length of the mtDNA molecule was estimated to be about 16.44 kb in P. chinensis and 16.31 kb in P. japonicus, Sequence divergence (p) of mtDNA between two species estimated by using Upholt's (1977) fomula was $13.7\%$.

• Journal of Life Science
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• v.30 no.12
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• pp.1063-1069
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• 2020

Two crucian carp species (Carassius auratus and C. cuvieri) inhabit Lake Yedang in South Korea, and C. auratus is known to be native to Korea. Classification of these two freshwater fish species is often confused because of their morphological similarity. To distinguish the two species, we conducted phylogenetic and population genetic analyses of C. auratus and C. cuvieri based on their mitochondrial DNA sequences of the cytochrome b gene (CYTB). We also compared our partial CYTB sequence (<1,056 bp) with 10 Chinese, nine Japanese, and two Russian crucian carp fishes. The results of our phylogenetic analysis showed that C. auratus and C. cuvieri were clearly divided into two phylogroups. The nucleotide diversity (π) of C. auratus from Korea, China, and Japan showed a range of 0.146%~0.421%, while the range of π of C. cuvieri from Korea and Japan was lower than those of C. auratus (0.0%~0.054%). Moreover, the comparison of CYTB divergence among crucian carp fishes in China, Japan, and Korea indicated that Korean Carassius fishes were distantly related to those from China and Japan, with two exceptions: the pairwise Fst value between Korean C. auratus and northern Chinese C. auratus was not significantly different. In addition, no significant genetic divergence between Korean and Japanese C. cuvieri was detected. We conclude that, despite the morphological similarities, C. auratus and C. cuvieri should be considered as separate freshwater fish resources in conservation efforts for genetic diversity.

• ALGAE
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• v.34 no.4
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• pp.277-288
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• 2019

Freshwater red algae of the order Batrachospermales are poorly studied in India and Nepal, especially on a molecular basis. During a survey in northeast India and east Nepal, six populations of the genus Sheathia were found and analyzed using molecular and morphological evidence. Phylogenetic analyses based on the rbcL gene sequences grouped all populations in a large clade including our S. arcuata specimens and others from several regions. Sheathia arcuata represents a species complex with a high sequence divergence and several smaller clades. Samples from India and Nepal were grouped in three distinct clades with high support and representing new cryptic species: a clade formed by two samples from India, which was named Sheathia assamica sp. nov.; one sample from India and one from Nepal formed another clade, named Sheathia indonepalensis sp. nov.; two samples from Nepal grouped with sequences from Hawaii and Indonesia (only 'Chantransia' stages) and gametophytes from Taiwan, named Sheathia dispersa sp. nov. Morphological characters of the specimens from these three species overlap one another and with the general circumscription of S. arcuata, which lacks the heterocortication (presence of bulbous cells in the cortical filaments) present in other species of the genus Sheathia. Although the region sampled is relatively restricted, the genetic diversity among specimens of these three groups was high and not closely related in the phylogenetic relationship with the other clades of S. arcuata. These data corroborate information from other groups of organisms (e.g., land and aquatic plants) that indicates this region (Eastern Himalaya) as a hotspot of biodiversity.

• Animal cells and systems
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• v.13 no.3
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• pp.323-329
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• 2009

We analyzed partial sequences of cytochrome b (cyt-b), a mitochondrial DNA (mtDNA) gene, to determine the genetic relationships between six horsehead fish species: Branchiostegus japonicus, Branchiostegus albus, Branchiostegus auratus, Branchiostegus argentatus, Branchiostegus wardi, and an unidentified Branchiostegus species. The specimens were collected in Korea, China, Japan, and Vietnam. We compared their molecular phylogenetic relationships inferred from mtDNA cyt-b sequences with an osteological analysis. The unidentified species, B. sp., was similar to B. albus in terms of the lack of triangular silver-white dot at the posterior region of eyes (vs. large one present in B. japonicus), but was also similar to B. japonicus in terms of the presence of a straight-shaped first hemal spine (vs. a curve-shaped hemal spine in B. albus). Analysis of the mtDNA cyt-b sequences indicated that the smallest estimated sequence divergence was between the B. japonicus and B. sp. (0.70-0.94%), whereas the largest difference was between B. auratus and B. argentatus (23.06-23.36%). Both the maximum parsimony and maximum likelihood trees showed that the B. sp. was closely clustered with B. japonicus, and that B. auratus was most distant from the other species. When comparing the osteological characters, UPGMA tree showed that the B. japonicus and B. sp. were the most closely clustered species, and B. auratus was the most distantly clustered fish relative to the other species. The shape of the nasal, otolith and first hemal spine was informative for distinguishing B. auratus from the other species. These osteological differences were consistent with the differences in mtDNA.

• Parasites, Hosts and Diseases
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• v.34 no.4
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• pp.259-266
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• 1996

The taxonomic validity of morphological group III Accnthamoeba app. is uncertain. In the present study. six type strains of group III Aconthamoeba spry. , A. culbertsoni, A. heniyi, A. pustulosc, A. palestinensis, A. royrebn and A. lenticulnto were subjected for the evaluation or their taxonomic validity by comparison of the isoeneyme patterns by isoelectic focusing on polyacrylamide gels, mitochondrial DNA (Mt DNA) restriction fragment length polymorphism (RFLP) . and small subunit ribosomal DNA (ssu rDNA) PCR-RFLP patterns. The Mt DNA RFLP patterns were heterogeneous between the species. The type strains of A. pclestinensls and A. pustulosc showed almost identical patterns of isoenrymes and rDNA PCR-RFLP with an estimated sequence divergence of 2.6%. The other species showed heterogeneous patterns of isoenxymes and rDNA PCR- RFLP. It is likely that A. pustuLosc is closely related with A. palestinensis and that the former may be regarded as a junior synonym of the latter.

• Animal Systematics, Evolution and Diversity
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• v.28 no.3
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• pp.215-219
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• 2012

To examine genetic divergences of two endemic Sorex caecutiens subspecies from Korea (S. c. hallamontanus in Korean Jeju Island and S. c. annexus in the mainland Korean Peninsula), we obtained partial cytochrome oxidase I (COI) sequences (429 bp) and complete cytochrome b sequences (1,140 bp) from the two Korean subspecies, and we compared these sequences to the corresponding sequences of S. caecutiens, obtained from GenBank. We found that Jeju S. c. hallamontanus is one of three clades within S. caecutiens, with an average Jukes-Cantor distance of 1.57% in the COI sequences and the distance of 2.07% and 11 fixed site differences in the cytochrome b sequences, indicating that Jeju S. c. hallamontanus is one endemic subspecies with concordant genetic distinctness, although further analyses with nuclear DNA sequences are necessary to confirm these findings. However, S. c. annexus from the mainland Korean Peninsula was not divergent from S. c. macropygmaeus from northeastern China and adjacent Russia, indicating that S. c. annexus from the mainland Korean Peninsula is another endemic subspecies with only morphological differences, although it is necessary to reexamine the subspecies status of S. c. annexus.

• Fisheries and Aquatic Sciences
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• v.6 no.4
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• pp.180-186
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• 2003

The full-length cDNA encoding the pre-protein growth hormone (sfGH) from spotted flounder (Verasper variegatus) was amplified by the rapid amplification of cDNA ends (RACE) using degenerated oligonucleotide primers derived from conserved growth hormone sequences. It consists of 901 nucleotides in length, including the coding region of 609 nucleotides, 111 nucleotides of a 5' untranslated region, and 181 nucleotides of a 3' untranslated region. The conserved polyadenylation signal (AATAAA) lies 12 bases upstream from the poly (A) tail. The deduced amino acid sequence shows an open reading frame encoding a pre-protein of 203 amino acids and a putative signal peptide of 17 amino acids, suggesting that the mature hormone consists of 186 amino acids. The analyses of sfGH reveal some unique structural features. The repetitive sequences are located in the 5' untranslated region of sfGH cDNA and consist of tandem arrays of imperfect direct repeat monomers. Moreover, sfGH contains six Cys residues, as opposed to four or five in other GHs, and it is clearly distinguishable from olive flounder (Paralichthys olivaceus) GH, which lacks a region corresponding to residues 175-188 in alignment positions. It has important implications from an evolutionary standpoint, suggesting possible divergence among flatfishes.

• ALGAE
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• v.33 no.2
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• pp.157-166
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• 2018

Cryptic species complexes are increasingly recognized in phycological research, obscuring taxonomy and raising questions about factors influencing speciation. A recent exploration of kelp genetic diversity on Haida Gwaii, British Columbia revealed the existence of a new species, Saccharina druehlii, which is cryptic with Saccharina sessilis. This suggests that molecular investigations further north may be required to elucidate the taxonomy and evolutionary history of this lineage. Although, for several decades, S. sessilis was considered a single highly variable species, its taxonomy has been far from straightforward. In particular, Hedophyllum subsessile (Areschoug) Setchell is now recognized as a synonym of S. sessilis in North America, but as a growth form of Saccharina bongardiana in Far East Russia. To resolve this taxonomic confusion, we sequenced mitochondrial (CO1-5P) and nuclear (internal transcribed spacer) markers of S. sessilis populations from the Aleutian Islands, Alaska, USA. Interestingly, none of our sequences matched S. sessilis sensu stricto. Instead, CO1-5P sequences from populations in the central and eastern Aleutians matched exactly S. druehlii with increasing sequence divergence occurring westward. Samples from Attu, the western-most island, composed a genetic group that clearly represents Kjellman's concept of Hafgygia bongardiana f. subsessilis and is distinct enough from S. druehlii and S. sessilis to potentially constitute a distinct species. Therefore, Saccharina subsessilis comb. nov. is proposed for this entity. Our results suggest the existence of a species complex at the crown node of S. sessilis and thus further investigation of Saccharina in Alaskan waters should be conducted to reconstruct the evolutionary history of this fascinating lineage.

• Korean Journal of Ichthyology
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• v.18 no.2
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• pp.78-86
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• 2006

We examined the genetic diversity in intra-populations of Korean shiner, Coreoleuciscus splendidus, in six major rivers (Bukhan, Namhan, Geum, Osipcheon, Nakdong and Seomjin river) of Korea based on two different mitochondrial genes, the mitochondrial cytochrome b and the 16S rRNA. Analysis of sequence variation in a 657-bp segment of the mitochondrial cytochrome b gene revealed deep divergence among populations (98.2~99.9%) and high genetic diversity from geographically isolated populations. Intra-specific variation in this 697-bp segment of the 16S rRNA gene sequences was very low and nearly identical. Six isolate populations of C. splendidus showed a high similarity (97.7%~99.7%). This result may be indicative of a complex history of connection and isolation of the rivers in the Korea peninsula.